deadhead

A deadhead is a spent flower head that should be removed to encourage new blooms; the verb means to remove such flowers: I spent the morning deadheading the roses.

In transportation, deadhead describes traveling empty—a truck returning without cargo, or a crew member riding as a passenger to reposition: The pilot deadheaded back to Chicago.

As slang, a deadhead is a dull, unproductive person. (Capitalized Deadhead is a fan of the Grateful Dead.)